The present invention relates to a ball joint mechanism which is adapted to permit setting of two members relative to each other, said members forming part of a settable device for gas transport, whereby one of said members preferably consists of a gas conduit and the other member preferably of a nozzle which is connected with said gas conduit and settable in various positions in relation thereto, and whereby the device for gas transport preferably is a settable device for the exhaustion or extraction of unhealthy gases from workplaces.
Ball joint mechanisms for the above purpose are known from the U.S. Pat. No. 4,540,202. In this publication there is schematically shown a ball coupling, but this is not settable and adjustable in its friction distance.
Ball joint mechanisms comprising two balls which cooperate with a spring element are known from the U.S. Pat. No. 1,827,432 and the FR-PS 699 369, but in these prior art ball joint mechanisms it is not possible to set or readjust the spring force by simple measures.
The object of the present invention has therefore been to permit, at a ball joint mechanism of the above type, setting or readjustment by hand of the spring forces.
By providing the ball joint mechanism with said characterizing features, its spring force can be set or readjusted by hand very quickly and precisely by changing the mutual position of the two members of the joint housing. By being able to carry out the change of the spring force in this way, no operations need to be done in the ball joint mechanism nor are any special tools required.